Multinuclear magnetic resonance: sign of ¹J(¹⁹⁵Pt–¹³C), and ¹⁹⁵Pt chemical shifts in carbonyl complexes of platinum(II)

Anderson, G. K., Cross, R. J. and Rycroft, D. S. (1980) Multinuclear magnetic resonance: sign of ¹J(¹⁹⁵Pt–¹³C), and ¹⁹⁵Pt chemical shifts in carbonyl complexes of platinum(II). Journal of Chemical Research, Synopses(7), pp. 240-241.

Abstract

[Selected text in lieu of Abstract] In a recent study of the ¹³C n.m.r. spectra of some carbonyl and acyl complexes of platinum(II) it was noticed that the temperature dependence of |¹J(¹⁹⁵Pt–¹³C)| could be positive or negative. As a previous rationalisation of the temperature dependence of ¹J(¹⁹⁵Pt–³¹P) could not account for this if all the ¹J(¹⁹⁵Pt–¹³C) values were positive, it appeared desirable to determine the signs experimentally.
We have now performed ¹⁹⁵Pt and ¹³C selective irradiation experiments while obtaining ³¹P–{¹H_noise} pulsed Fourier transform spectra of compounds (1)–(4). ¹⁹⁵Pt tickling experiments looking for symmetrical splitting of ³¹P lines [γ(¹⁹⁵Pt)B₂ = 20–100 Hz; more irradiation power was used to find an initial perturbation] gave the sign of ¹J(¹⁹⁵Pt–¹³C)/²J(³¹P–¹³C). ¹³C irradiation to cause selective decoupling [(1) and (3)] or collapse [(2) and (4)] of ²J(³¹P–¹³C) gave the sign of ¹J(¹⁹⁵Pt–¹³C)/¹J(¹⁹⁵Pt–³¹P). The results are shown in the Table on the basis that ¹J(¹⁹⁵Pt–³¹P) is positive.
Thus for carbonyl trans to a tertiary phosphine, halide, or aryl group, ¹J(¹⁹⁵Pt–¹³C) is positive, and it is likely that all 'large' ¹J(¹⁹⁵Pt–¹³C) values are positive, in agreement with theoretical calculations.

• Item Type: Articles
• Keywords: NMR spectroscopy, multiple resonance.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Rycroft, Dr David
• Authors: Anderson, G. K., Cross, R. J., and Rycroft, D. S.
• Subjects: Q Science > QD Chemistry
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Journal of Chemical Research, Synopses
• Publisher: Royal Society of Chemistry
• ISSN: 0308-2342